Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may transmit feedback to a base station indicating phase values for sub-bands in a bandwidth part (BWP). The base station may use the phase feedback to perform precoding on a set of beams. To support a reduced payload overhead for the feedback, the UE may implement differential phase feedback. For example, the UE may divide the BWP into a number of sub-band groups and may generate, for each sub-band group of each beam, a first set of bits indicating an absolute phase value for a first sub-band of the sub-band group. The UE may additionally generate a second set of bits indicating differential phase values for the other sub-bands of each sub-band group. The UE may report the first and second sets of bits for the beams to the base station for precoding.

Various solutions pertaining to reporting of best wideband (WB) channel quality indicator (CQI) in mobile communications are described. An apparatus implemented in a user equipment (UE) calculates a value of a modified wideband channel quality indicator (WB-CQI) with respect to a wideband based on CQI values of a subset of subbands of a plurality of subbands in the wideband. The apparatus then reports the modified WB-CQI to a network. In calculating the value of the WB-CQI, the apparatus excludes one or more subbands from the plurality of subbands to result in the subset of subbands used in calculating the value of the WB-CQI. A respective CQI value of each of the excluded one or more subbands is lower than a respective CQI value of each of the subset of subbands.

Certain aspects of the present disclosure provide techniques for reporting beam-strength related Type-II channel state information (CSI) coefficient feedback.

A method for channel smoothing with transmit beamforming includes transmitting, by a first device, a non-data-packet (NDP) frame to a second device. The method also includes receiving, by the second device, the NDP frame and transmitting a compressed report to the first device. The method further includes receiving, by the first device, the compressed report and deriving a first beamforming matrix from the compressed report. A second beamforming matrix is generated employing a processing known to the second device, and a data frame is transmitted to the second device using the second beamforming matrix.

Some embodiments of the present disclosure provide beam indication solutions. A first solution relates to absolute beam indication and a second solution relates to differential beam indication. Through, for example, information determined using sensing, these beam indication solutions allow for information transfer between transmit receipt point and user equipment to occur on a relatively narrow beam. By reducing scanning, a solution based on beam indication aspects of the present application reduce overhead and, consequently, reduce latency. Another benefit of a narrow beam is improved spectral efficiency. The sensing may allow for a relationship between a beam and an external environment to be established. The relationship allows for a beam to be indicated in a direct and agile manner.

A method comprises: configuring multiple reporting modes for multi-level based transmitter (TX) beam index reporting for a particular beam/antenna panel group from a plurality of beam/antenna groups, wherein the multiple reporting modes includes at least one of a full reporting mode configuration for the particular beam/antenna panel group, a full reporting mode configuration common for the plurality of beam/antenna panel groups, a differential reporting mode, and a partial reporting mode, selecting a reporting mode from the multiple reporting modes, and sending a report based on the selected reporting mode.

Aspects relate to configuration of a Layer 1 (L1) measurement report. A radio access network (RAN) node (e.g., a base station) can transmit at least one report setting, each associated with a selected information type, to a wireless communication device (e.g., a UE). The selected information type may be selected from a first information type and a second information type. When a report setting is associated with the first information type, the wireless communication device can transmit the L1 measurement report including both beam measurements and beam identifiers corresponding to the beam measurements for the report setting. When the report setting is associated with the second information type, the wireless communication device can exclude the beam identifiers from the L1 measurement report including the beam measurements for the report setting. Other aspects, features, and examples are also claimed and described.

Disclosed are an information transmission method and device for improving CSI feedback performance and providing finer CSI feedback. The information transmission method of the present invention comprises: determining a quantity of layers transmitted on a channel; and determining, according to the quantity of the layers transmitted on the channel, channel state information (CSI) fed back for the respective layers, and transmitting the same, and the CSI fed back for the respective layers comprises information about multi-level beams.

A wireless user equipment (UE) may employ any of various mechanisms for reporting signal quality measurements to a wireless network. The UE may impose a time delay between measurement and reporting, based on a delay parameter K. The UE may average measurements obtained at different measurement instances. The UE may employ any of various schemes for prioritizing transmission of one type of report over another, when temporal collisions occur between different types of report. The UE may employ a differential report that includes a state for indicating that a beam is not workable. The UE may employ a beam index that includes a state for indicating an invalid beam. A base station may receive a signal quality report and determine workability of a beam, e.g., by triggering a report of channel state information.

Aspects relate to configuration of a Layer 1 (L1) measurement report. A radio access network (RAN) node (e.g., a base station) can transmit at least one report setting, each associated with a selected information type, to a wireless communication device (e.g., a UE). The selected information type may be selected from a first information type and a second information type. When a report setting is associated with the first information type, the wireless communication device can transmit the L1 measurement report including both beam measurements and beam identifiers corresponding to the beam measurements for the report setting. When the report setting is associated with the second information type, the wireless communication device can exclude the beam identifiers from the L1 measurement report including the beam measurements for the report setting. Other aspects, features, and examples are also claimed and described.